Convertible burner with heating of flame sensing element

ABSTRACT

A burner convertible for use with different fuels has a flame sensing element with burner ports from different fuel chambers directed toward the flame sensing element.

United States Patent [191 Dykzeul July 23, 1974 [56] References Cited CONVERTIBLE BURNER WITH HEATING Inventor: Theodore J- Dykzeul, L08 Angeles, 2,750,997 6/1956 Reuter 431/284 Calif. v 3,395,968 8/1968 Mobarry et al'. 43l/50 X [73] Assignee: Robertshaw Controls Company,

Richmond, v Primary ExammerEdward G. Favors Attorney, Agent, or FirmAnth0ny A. OBnen [22] Filed: June 18, 1973 [21] Appl. No.1 371,017 57 ABSTRACT A burner convertible for use with different fuels has a [52] US. Cl. 431/80 flame sensing element with burner ports from different Int. fuel chambers directed toward the flame sensing ele- [58] Field of Search 431/284, 285, 50, 80, 347, m

6 Claims, 2 Drawing Figures l v 84 I02 82 54 IOI 8o 68 I52 78 I t I03 CONVERTIBLE BURNER WITH HEATING OF FLAME SENSING ELEMENT BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to burners and, in particular,.to burners convertible for burning different fuels and which have flame sensing elements.

2. Description of the Prior Art The prior art, as exemplified by U.S. Pat. No. 2,474,547, 2,581,590, No. 2,610,984 and No. 2,993,533, contains many burners with a burner port directed toward a flame sensing element. In burners which are convertible for use with different fuels, flames impinging upon the flame sensing element from a single burner port will vary in intensity with the different fuels causing, in some instances, insufiicient heating of the element, and in other instances, excessive flames. While it is known to change burner port members to accommodate different fuels, such changes are often difficult to make or are expensive.

SUMMARY OF THE INVENTION The invention is summarized in that a burner apparatus selectively adaptable for operation by first and second fuels includes a burner member having first and second chambers, a flame sensing element, means for supporting the flame sensing element adjacent to the burner member, input means for communicating from a supply passageway to the first and second chambers, said input means being capable of selectively communicating from the supply passageway to the second chamber to adapt the burner for operation by the second fuel, said burner member having a first burner port from the first chamber directed toward the flame sensing element, said first port being capable of sustaining a flame of sufficient size from the first fuel tooperate the flame sensing element, said burner member having a second burner port from the second chamber directed toward the flame sensing element, and said second port being capable of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element.

An object of the invention is to construct a burner which produces a relatively constant intensity flame impinging upon a flame sensing element when used with different fuels.

Another object of the invention is to provide a supplementary flame for a flame sensing element when a burner is operated on a relatively low heat-generating capacity fuel.

An advantage of the invention is that when a burner having a separate burner port directed toward a flame sensing element is converted for use with a different fuel, it is unnecessary to change members solely associated with the separate burner port.

An additional feature of the invention is the provision of inner, intermediate and outer coaxial tubular sections forming an annular burner member wherein the inner tubular section has vertically spaced first and second burner ports and one end of the intermediate tubular section is joined to the inner tubular section between the first and second burner ports.

Other objects, advantages and features of the invention will become apparent from the following descrip- 2 tion of the preferred embodiment taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational cross section view of a burner apparatus in accordance with the invention and adapted for operation with a first fuel.

' FIG. 2 is a view similar to FIG. I but with the burner apparatus adapted for operation with a second fuel.

DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in FIGS. 1 and 2, the present invention is embodied in a fuel burner apparatus having a burner member indicated generally at 10, input facilities indicated generally at 11, and a flame sensing element 68. The input facilities 11 are any suitable facilities for selecting the mode of operation of the burner member 10 by a supply of a high-heat-generating-capacity-per-unit volume fuel, or alternately, by a supply of a low-heatgenerating-capacity-per-unit-volume fuel.

The high-heat-generating-capacity-per-unit-volume fuel is a gas which is employed at a relatively high pressure or which generates relatively more units of heat per unit volume at a standard temperature and pressure, and the low-heat-generating-capacity-per-unitvolume fuel is a gas which is employed at a relatively low pressure or which generates relatively less unitsof heat per unit volume at a standard temperature and pressure. Propane is referred to as an example of a conventionally employed high-heat-generating-capacityper-unit-volume fuel and natural gas is referred to as an example of a conventionally employed low-heatgnerating-capacity-per-unit-volume fuel.

The burner apparatus can be employed in a wide variety of systems and applications and any fuel'control device (not shown) suitable for any of such systems and applications can be connected to the input facilities 1 1 to operate the burner apparatus. One example of asuitable'fuel control device is the plural rate fuel control device disclosed in U.S. Patent Application Ser. No.

98,246 by Jay R. Katchka and Henry C. Braucksiek filed on Dec. 15, 1970, now U.S. Pat. No. 3,762,639, issued Oct. 2, 1973.

A bottom plate 56 secured to the burner member 10 has a plurality of circularly disposed openings 58 and a central opening 60 within which a tubular support 62 is suitably mounted. The upper end of the tubular support 62 is slotted and has a dimpled portion 64 which mates with a grooved portion 66 of the flame sensing element 68 for supporting the element 68 along the axis and above the burner member 10. The flame sensing element 68 is any suitable thermo-responsive device, such as a shielded thermocouple which can be used to operate facilities, such as a magnetic safety valve (not shown), to prevent release of hazardous gas in the event that the flame of the burner is extinguished by air drafts, loss of fuel, etc.

The burner member 10 has an outer tubular section 12, an intermediate tubular section 14 and an inner tubular section 16 which areall coaxial. The upper ends 101 and 102 of the respective outer and inner tubular sections 12 and 16 are suitably secured together while the upper end 103 of the intermediate tubular section 14 is suitable secured to the inner tubular section 16 at a circular joining line spaced downward from the upper end 102. Lower flanged portions 18 and 20'of the respective tubular sections 14 and 16 are secured to the lower end of the outer tubular section 12. The tubular sections l2, 14 and 16 form coaxial annular outer and inner chambers 22 and 24. The intermediate tubular section 14 forms a wall between the chambers 22 and 24 with a plurality of circumferentially-spaced and outward-facing burner ports 48 which are aligned or radially basically concentric with respective circumferentially-spaced and outward-facing burner ports 50 in the outer tubular section 12. The burner ports 48 are relatively smaller than the burner ports 50 and have a size capable of producing suitable flames through the ports 50 from propane gas supplied to the inner chamber 24 while the burner ports 50 have a size capable of producing suitable flames from natural gas supplied to the outer chamber 22. Exact radial center line alignment of the ports 48 and 50 is not required, only significant alignment to ensure that a substantial portion of the propane gas issuing from the ports 48 passes freely through the ports 50.

The input facilities 11 include a bevelled input opening 26 in the intermediate tubular section 14 and an input opening 28 in the outer tubular section 12. The opening 26 is aligned with the opening 28. A fitting member or nipple 30 is suitable secured within the opening 28 of the outer tubular section 12 and has a threaded portion 32 which mates with a threaded portion 34 of a fitting member 36 which has a supply passageway 38. A reversible tubular member 40 has a ridge portion 42 formed at one endfor being secured between the outward end of the fitting member 30 and an inward formed flange 44 of the fitting member 36. The other end 46 of the tubular member 40 is tapered such that it is fitted with the bevelled opening 26 when installed between the fitting members 30 and 36 as shown in FIG. 1 The tubular member 40 has a diameter designed to easily fit within the passageway 38 as shown in FIG. 2 for allowing communication between the passageway 38 and the chamber 22 when installed as shown in FIG. 2.

The inner tubular section 16 forms an inner wall of the burner member 1 and has deformed portions 52 and 152 with burner ports 54 and 154 formed therein such that the prots 54 and 154 are directed inwardly and upwardly toward the flame sensing element 68. The deformed portion 52 and port 54 are below the junction of the end 103 of the intermediate tubular section 14 while the deformed portion 152 and the port 154 are above the junction such that the port 54 is from the inner chamber 24 and the port 154 is from the outer chamber 22. The port 54 has a size capable of use with propane gas to sustain a flame of propane gas having sufficient size to operate the flame sensing element 68. The port 154 is larger than the port 54 and has a size capable in combination with port 54 of use with natural gas to sustain a flame of natural gas having sufficient size to operate the flame sensing element 68.

An upward flaring flame spreader 72 disposed in the path of burning streams of fuel extending horizontally from the burner ports 50 is attached by legs 76 to the outer tubular section 12'. A shield retainer 78 disposed above the ports 50 has spokes 80 connected to a collar 82 which is secured to the outer tubular section 12. A frusto-conical flame shield 84 is connected by outward bent tabs 86 extending through openings 88 between the spokes of the shield retainer 78. A spaced top 92 bent horizontally from a leg extending upward from the shield 84 is secured by inward bent tabs 94 on legs 96 extending from the shield 84.

In operation of the burner apparatus of FIGS. 1 and 2 with propane, the tubular member 40 is inserted between the fitting members 30 and 36 as shown in FIG. 1 to secure the tapered end 46 in the bevelled opening 26 to provide communication between the supply passageway 38 to the inner chamber 24. Propane gas passes from the supply passageway 38 through the member 40 into the inner chamber 24. The propane gas in the inner chamber 24 sustains a stream of burning propane gas from the burner port 54 which impinges on the flame sensing element 68. Since the port 54 is designed for propane gas, the flame has a size sufficient to operate the element 68 without being excessive. Propane gas also passes out from the burner ports 48 from the chamber 24 to produce streams of propane gas which pass through the outer chamber 22 and the outer ports 50 to sustain flames from the ports 50. The ports 48 are designed for operation by propane gas and hence produce suitable flames from the burner ports 50. Since ridge 42 of the tubular member 40 is tightly secured to the flanged portion of the fitting member 36 and the tapered end 46 of the tubular member 40 is tightly secured in the bevelled opening 26, the tubular member 40 communicates between the supply passageway 38 and the inner chamber 24 to the exclusion of the outer chamber 22 and substantially no propane gas passes from the supply passageway 38 to the outer chamber 22 except through the ports 48. Since the ports 50 are aligned with the ports 48 and are larger than the ports 48, no substantial gas pressure is produced in the outer chamber 22 and substantially no flame is produced from the port 154.

In operation of the burner apparatus with natural gas, the tubular member 40 is reversed to extend into the supply passageway 38 and allow communication from the passageway 38 to both of the chambers 22 and 24. Natural gas from the supply passageway 38 flows through the tubular member 40 and the opening 28 into the outer chamber 22 and through the opening 26 into the inner chamber 24. The natural gas in the chamber 22 and 24 sustains streams of burning natural gas from both burner ports 54 and 154. Since the burner port 54 is designed for propane, natural gas solely from the port 54 would produce a flame which is insufficient to properly operate the flame sensing element 68. Burning gas from the larger port 154 supplements the burning gas from the port 54 to the extent that a flame is sustained which is sufficient to operate the flame sensing element 68. The natural gas in the outer chamber 22 also produces suitable flames from the ports 50.

The openings 58 in the bottom plate 56 provide adequate air for mixing with gas from the ports 54 and 154 to produce suitable flames. The spacing of the cover 92 by the legs 90 and 96 provides ventilation for the flame from the burner ports 54 and 154.

As an example of suitable sizes for the burner ports 54 and 154 for operation at selected pressures, the port 54 is formed with a diameter of 0.008 inches and the port 154 is formed with a diameter of 0.011 inches. Propane gas applied at 11 inches of water column to the inner chamber 24 produces a flame from the port 54 which produces approximately 500 Btu per hour to hold the flame sensing element 68 in an operated condition. Natural gas applied at 4 inches of water column to both of the chambers 22 and 24 produces a flame generating approximately 500 Btu per hour from both of the ports 54 and 154. I In a dual rate system where the burner apparatus operates at a standby rate and at a high rate, FIGS. 1 and 2 illustrate the high rate of operation. At the standby rate with either propane or natural gas, fuel pressure in the chambers 22 and 24 is relatively low so that flames from ports 50 extend upward along the outer surface of the outer tubular section 12 between the spokes 80 and 'inward over the top of the burner member against the flame sensing element 68 to maintain the operated condition of the flame sensing element 68.

Since many variations, modifications and changes in detail may be made to the present embodiment, it is intended that all matter contained in the foregoing description or shown on the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A burner apparatus selectively adaptable for operation by first and second fuels comprising a burner member having first and second chambers,

a flame sensing element,

means for supporting the flame sensing element adjacent to the burner member,

input means for communicating from a supply passageway to the first and second chambers,

said input means having a first operating position for communicating from the supply passageway to said first chamber to the exclusion of the second chamber and having a second operating position for communicating from a supply passageway to both the first and second chambers,

said burner member having a first burner port from the first chamber directed toward the flame sensing element,

said first port being capable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element,

said first port being incapable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element,

said'burner member having a second burner port from the second chamber directed toward the flame sensing element, and

said second port in combination with the first port being capable of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element.

2. A burner apparatus selectively adaptable for operation by first and second fuels comprising a burner member having first and second chambers,

a flame sensing element,

means for supporting the flame sensing element adjacent to the burner member,

input means for communicating from a supply passageway to the first and second chambers,

said input means being capable of selectively communicating from the supply passageway to the second chamber to adapt the burner for operation by the second fuel,

said burner member having a first burner port from the first chamber directed toward the flame sensing element,

said first port being capable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element,

said burner member having a second burner port from the second chamber directed toward the flame sensing element,

said second port being capable of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element,

said burner member being annular about a vertically extending axis and having an inner wall through which both the first and second ports exit inward, and

said supporting means supporting the flame sensing element within the annular burner member.

3. A burner apparatus as claimed in claim 2 wherein the burner member includes an inner tubular section having the first and second burner ports formed in vertically spaced positions therein,

an intermediate tubular section joined at one end to the inner tubular section between the first and second burner ports, and

an outer tubular section joined at one end to one end of the inner tubular section and joined at the other end to the other ends of both the intermediate tubular sections and the inner tubular sectionto form the first and second chambers.

4. A burner apparatus adaptable for operation byfirst and second fuels comprising I a burner member containinga first chamber and a second chamber with a wall between the first and second chambers;

a flame sensing element;

means for supporting the flame sensing element adjacent the bumer member; I

input means having a first operating position for communicating from the supply passageway to the first chamber to the exclusion of the second chamber and having a second operating position for comm unicating from a supply passageway to both the first and second chambers; and

said burner member having a first burner port for producing a stream of the first fuel directed toward the element from the first chamber, a second burner port for producing a stream of the second fuel directed toward the element from the second chamber, a third burner port directed away from the element for producing a stream of the second fuel from the second chamber, and a fourth burner port in the wall directed away from the element for producing a stream of the first fuel from the first chamber through the third port.

5. A burner apparatus as claimed in claim 4 wherein the burner member is annular about a vertically extending axis and has an outer annular chamber, aninner annular chamber, an annular wall between the outer and inner chambers, a plurality of outwardly directed third burner ports from the outer chamber, a plurality of outwardly directed fourth burner ports through the annular wall, each fourth port aligned with a third port, and an inner wall through which both the first and second ports exit inward, and

the supporting means supports the flame sensing ele ment within the annular burner member.

6. A burner apparatus selectively adaptable for operation by a first gaseous fuel and a second gaseous fuel where the first fuel has a higher heat-generating capacity per cubic foot than a second fuel, the burner apparatus comprising an annular member about a vertically extending axis and having an inner tubular section having a first burner port and a second burner port both directed inward and upward toward the axis of the annular burner member, the first burner port and the second burner ports having vertically spaced positions, an outer tubular section with a plurality of horizontally-directed and circumferentially-spaced third burner ports, an intermediate tubular section with a plurality of horizontally-directed and circumferentially-spaced fourth burner ports, the fourth burner ports being smaller than the third burner ports, each fourth burner port aligned with a respective third burner port, the intermediate tubular section being joined at one end to the inner tubular section between the first and second burner ports, one end of the outer tubular section being joined to one end of the inner tubular section, and the other end of the tubular section being joined with the other ends of both the intermediate and inner tubular sections to form coaxial inner and outer annular chambers;

a flame sensing element;

means for supporting the flame sensing element along the axis and above the annular burner member;

input means having a first operating position for communicating from the supply passageway to the inner chamber to the exclusion of the outer chamber and having a second operating position for communicating from a supply passageway to both the inner and outer chambers;

said first burner port being from the inner chamber and being capable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element; and

said second burner port being from the outer chamber and being capable in combination with the first burner port of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element. 

1. A burner apparatus selectively adaptable for operation by first and second fuels comprising a burner member having first and second chambers, a flame sensing element, means for supporting the flame sensing element adjacent to the burner member, input means for communicating from a supply passageway to the first and second chambers, said input means having a first operating position for communicating from the supply passageway to said first chamber to the exclusion of the second chamber and having a second operating position for communicating from a supply passageway to both the first and second chambers, said burner member having a first burner port from the first chamber directed toward the flame sensing element, said first port being capable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element, said first port being incapable of sustaining a flame of sufficient size from the first fuel to operate the flaMe sensing element, said burner member having a second burner port from the second chamber directed toward the flame sensing element, and said second port in combination with the first port being capable of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element.
 2. A burner apparatus selectively adaptable for operation by first and second fuels comprising a burner member having first and second chambers, a flame sensing element, means for supporting the flame sensing element adjacent to the burner member, input means for communicating from a supply passageway to the first and second chambers, said input means being capable of selectively communicating from the supply passageway to the second chamber to adapt the burner for operation by the second fuel, said burner member having a first burner port from the first chamber directed toward the flame sensing element, said first port being capable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element, said burner member having a second burner port from the second chamber directed toward the flame sensing element, said second port being capable of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element, said burner member being annular about a vertically extending axis and having an inner wall through which both the first and second ports exit inward, and said supporting means supporting the flame sensing element within the annular burner member.
 3. A burner apparatus as claimed in claim 2 wherein the burner member includes an inner tubular section having the first and second burner ports formed in vertically spaced positions therein, an intermediate tubular section joined at one end to the inner tubular section between the first and second burner ports, and an outer tubular section joined at one end to one end of the inner tubular section and joined at the other end to the other ends of both the intermediate tubular sections and the inner tubular section to form the first and second chambers.
 4. A burner apparatus adaptable for operation by first and second fuels comprising a burner member containing a first chamber and a second chamber with a wall between the first and second chambers; a flame sensing element; means for supporting the flame sensing element adjacent the burner member; input means having a first operating position for communicating from the supply passageway to the first chamber to the exclusion of the second chamber and having a second operating position for communicating from a supply passageway to both the first and second chambers; and said burner member having a first burner port for producing a stream of the first fuel directed toward the element from the first chamber, a second burner port for producing a stream of the second fuel directed toward the element from the second chamber, a third burner port directed away from the element for producing a stream of the second fuel from the second chamber, and a fourth burner port in the wall directed away from the element for producing a stream of the first fuel from the first chamber through the third port.
 5. A burner apparatus as claimed in claim 4 wherein the burner member is annular about a vertically extending axis and has an outer annular chamber, an inner annular chamber, an annular wall between the outer and inner chambers, a plurality of outwardly directed third burner ports from the outer chamber, a plurality of outwardly directed fourth burner ports through the annular wall, each fourth port aligned with a third port, and an inner wall through which both the first and second ports exit inward, and the supporting means supports the flame sensing element within the annular burner member.
 6. A burner apparatus selectively adaptable for operation by a first gaseous fuel and a second gaseous fuel wherE the first fuel has a higher heat-generating capacity per cubic foot than a second fuel, the burner apparatus comprising an annular member about a vertically extending axis and having an inner tubular section having a first burner port and a second burner port both directed inward and upward toward the axis of the annular burner member, the first burner port and the second burner ports having vertically spaced positions, an outer tubular section with a plurality of horizontally-directed and circumferentially-spaced third burner ports, an intermediate tubular section with a plurality of horizontally-directed and circumferentially-spaced fourth burner ports, the fourth burner ports being smaller than the third burner ports, each fourth burner port aligned with a respective third burner port, the intermediate tubular section being joined at one end to the inner tubular section between the first and second burner ports, one end of the outer tubular section being joined to one end of the inner tubular section, and the other end of the tubular section being joined with the other ends of both the intermediate and inner tubular sections to form coaxial inner and outer annular chambers; a flame sensing element; means for supporting the flame sensing element along the axis and above the annular burner member; input means having a first operating position for communicating from the supply passageway to the inner chamber to the exclusion of the outer chamber and having a second operating position for communicating from a supply passageway to both the inner and outer chambers; said first burner port being from the inner chamber and being capable of sustaining a flame of sufficient size from the first fuel to operate the flame sensing element; and said second burner port being from the outer chamber and being capable in combination with the first burner port of sustaining a flame of sufficient size from the second fuel to operate the flame sensing element. 